Improving magnetic cooling efficiency and pulldown by varying flow profiles

• DOI: 10.1016/j.applthermaleng.2022.118945
• Publication Date: 2022-07-13T16:49:22Z
• Authors: M. Masche; J. Liang; K. Engelbrecht; C.R.H. Bahl
• Keywords: Cooling capacity; Solenoid; Reciprocating motion

Magnetic refrigeration systems are promising cooling solutions that employ the active magnetic regenerator cycle to achieve practical temperature spans and environmental benefits. The hydraulic system ensures a continuous flow of heat transfer fluid through with reciprocating in each bed is critical performance cycle. Hence, we investigate characteristics parallel circuit rotary system, which consists thirteen trapezoid-shaped regenerators, filled 295 g gadolinium spheres. Fluid controlled via electrically actuated solenoid valves (both piloted direct-acting) connected hot side. By varying percentage opening control valves, different blow fractions (or waveforms) could be investigated. objective study twofold: (i) assess whether imbalances exist cold-to-hot (cold blow) hot-to-cold (hot directions, (ii) determine there an optimal value fraction both maximize realize rapid pulldown. Flow resistance measurements demonstrate symmetric design resistances similar cold directions. Moreover, for studied 6 K 16 K, best was found about 41.6 %. For instance, at span, utilization 0.32, 1.4 Hz, increasing from 25.0 % enhanced capacity second-law efficiency 70 330 W 2.6 17.4 %, respectively. In turn, lower favored more magnetocaloric 30 faster establishing approximately 14 span when reduced 30.6 can benefit greatly allow operate either time-saving mode or energy-saving mode.